3-thioacetyl or benzoyl-alkane-1,4-diones

ABSTRACT

NOVEL 3-THIA-1,4 DIONES HAVING THE STRUCTURE:   R1-CO-C(-R6)(-S-R3)-CH(-R4)-CO-R2   WHEREIN R1 AND R2 ARE THE SAME OR DIFFERENT AND ARE EITHER HYDROGEN OR LOWER ALKYL, R3 IS EITHER HYDROGEN, LOWER ALKYL, ACYL, AROYL, BENZYL OR PHENYL AND EACH OF R4 AND R6 ARE THE SAME OR DIFFERENT AND ARE EITHER HYDROGEN OR LOWER ALKYL, SUCH 3-THIA-1,4 ALKANE DIONES BEING USEFUL IN ALTERING THE ORGANOLEPTIC PROPERTIES OF FOODSTUFFS.

U.S. Cl. 260-455 R 3 Claims ABSTRACT OF THE DISCLOSURE Novel 3-thia-l,4 diones having the structure:

Rs-S R4 wherein R, and R are the same or different and are either hydrogen or lower alkyl, R is either hydrogen, lower alkyl, acyl, aroyl, benzyl or phenyl and each of R and R United States Patent are the same or different and are either hydrogen or lower alkyl, such 3-thia-1,4 alkane diones being useful in altering the organoleptic properties of foodstuffs.

BACKGROUND OF THE INVENTION The present invention relates to novel 3-thia-1,4 alkane diones.

1 Artificial flavoring agents for foodstuffs have received increasing attention in recent years. In many areas, such food flavoring agents are preferred over natural flavoring agents at least in part because of the uniform flavor that maybe so obtained. For example, natural food flavoring agents such as extracts, essences, concentrates and the like are often subject to wide variation due to changes in the quality, type and treatment of the raw materials. Such variation can be reflected in the end product and results in unreliable flavor characteristics and uncertainty as to consumer acceptance and cost. Additionally, the presence of the natural product in the ultimate food may be undesirable because of increased tendency to spoil. This is particularly troublesome in convenience and snack food usage where, such products as dips, soups, chips, prepared dinners, canned foods, sauces, gravies and the like are apt to be stored by the consumer for some time prior to use.

The fundamental problem in preparing artificial flavoring agents is that of achieving as nearly as possible a "true flavor reproduction. This generally proves to be a difficult task since the magnetism for flavor development in many foods is not understood. This is notable in products having meaty and roasted flavor characteristics. It

"is also notable in products having vegetable-like and hydrolyzed vegetable protein-like and anise-like flavor characteristics.

Reproduction of roasted and meat flavors and aromas and vegetable-like and hydrolyzed vegetable protein-like and anise-like flavors and aromas has been the subject ofthe the long and continuing search by those engaged .in the production of foodstuffs. The severe shortage of foods, especially protein foods, in many parts of the world .has given rise to the need for utilizing non-meat sources of proteins and making such proteins as palatable and as meat-like as possible. Hence, materials which Will closely simulate or exactly reproduce the flavor and aroma of roasted meat products and liver products and vegetable products are required.

Moreover, there are a great many meat containing or meat based foods presently distributed in a preserved form. Examples being condensed soups, dry-soup mixes,

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dry meat, freeze-dried or lyophilized meats, packaged gravies and the like. While these products contain meat or meat extracts, the fragrance, taste and other organoleptic factors are very often impaired by the processing operation and it is desirable to supplement or enhance the flavors of these preserved foods with versatile materials which have either roasted meat or gravy-like or vegetable-like or meat-like or ham-like nuances.

Belgian Pat. 786,192, issued Jan. 12, 1973, provided a-ketothiols and indicated that such a-ketothiols gave rise to savory meat flavors. An example of such an a-ketothiol is Z-mercapto pentanone-3.

South African Pat. 69/4,539, dated June 26, 1969, discloses, for use as intermediates for subsequent reaction to form meat flavor compounds l,4-dithioacetyl-2,3-diketones having the structure:

0 o 1 0 H H (Alkyl) S (Alkyl) (Alkyl) S (Alkyl) See page 6 of said South African patent.

Nothing in the prior art, however. sets forth implicitly or explicitly the 3-thia-1,4-alkane diones or our invention and their unique and advantageous and unobvious flavor properties.

THE INVENTION The present invention provides novel 3-thia-l,4-alkane diones useful for altering the organoleptic properties of foodstuffs. Briefly, the novel compounds are 3-.thia-1,4- alkane diones having the formula:

3-Thioacetyl-2,5 hexanedione having the structure:

3-Mercapto-2,S-hexanedione having the structure:

3-Thiobenzoyl-2,5-hexanedione having the structure:

3-Thiopropyl-2,S-hexanedione having thestructure The novel compounds of our invention may be produced according to processes which comprise the steps of:

(i) providing a 2-ene-l,4 dione having the structure:

(ii) intimately admixing said 2-ene-l,4 dione with a thiol or thio acid having the formula R SH thereby providing a substituted or unsubstituted 2-thia substituted- '1,4-dione having the structure:

thereby providing a substituted or unsubstituted 2-thia alkane 1,4-dione having the structure:

Rs-S R4 Rr- -H Rr- 11: 0 0

R4 SR Such materials may, if desired, further be hydrolyzed to form 3-Inercapto furan having the structure:

and these 3-mercapto furans may be further reacted with an acylating or aroylating agent thus forming a new acyl or aroyl 3thia furan having the structure:

R4 SR7 wherein R and R are the same or different and are either hydrogen or lower alkyl, R is either hydrogen, lower alkyl, acyl, aroyl, benzyl or phenyl, R is the same or different and is either hydrogen or lower alkyl and R is aroyl or acyl different from R R or/and R may each be hydrogen in the event that in step (ii) the 2-ene-1,4 dione is admixed with a thio acid or thiol having the formula R SH in the presence of an organic base such as piperidine, pyridine, triethyl amine, quinoline or a-picoline or a mixture thereof.

The 2-ene-l,4 dione may be prepared by reacting 2,5- dialkoxy 2,5-dialkyl-2,5-dihydro furan with a weak acid hydrolysis agent such as 1% aqueous acetic acid under reflux conditions. The resulting material will be in the case of starting with 2,5-dimethoxy-2,5-dihydro-furan, cis-3- hexen-2,5-dione.

The resulting 2-ene-1,4 dione is then reacted Wltllfillhfil' a thiol or a thio acid having the formula R SH wherein R is either acyl or aroyl. Examples of such thiols and thio acids are:

thioacetic acid thiopropionic acid thiobutyric acid thioisobutyric acid thio-n-pentenoic acid methyl mercaptan ethyl mercaptan n-propyl mercaptan isopropyl mercaptan n-butyl mercaptan isobutyl mercaptan n-hexyl mercaptan n-octyl mercaptan n-nonyl mercaptan benzyl mercaptan thiophenol p-tolyl mercaptan m-tolyl mercaptan o-tolyl mercaptan thiocinnamic acid thiobenzoic acid Z-methyl-thiobenzoic acid 3-methyl-thiobenzoie acid I 4-rnethyl-thiobenzoic acid. 2,4-dimethy1-thiobenzoic acid 3,5-dimethyl-thiobenzoic acid.

Whether an organic base is used or not in the reaction with the 2-ene-l,4 dione with the thiol or thio acid having the formula R SH, the 2-ene-l,4 dione can be exemplified as follows: 7

Compound name R R2 R4 Methyl MethyL- Hydrogen.

.do do Methyl.

Do. I Ethyl.

- Ethyldo Do.

Ethyl..- MethyL. Methyl.

do Ethyl. Do.

do PropyL. 'Do.

- do Methyl Propyl.

Propyl.

3-propyl-3-hepten-2,5-dione. 4-methyl-3hepten-2,5-dione- 4-methyl-4oeten-3.6-dione 4 propyl-3-hepten-3,6-dione do Do.- Buty Do. do Ethyl. MethyL. Butyl Methyl. 3-propyl-3-nonen-2,5-dione. .do "do---" Propyl.

3buty1-3-hexen-2,5-dione...- do Methyl 'ButyI. 4-oeten-3,6-dione Ethyl Ethyl." Hydrogen As stated above, R and R can each be hydrogen for the purposes of these processes of our invention in the event that in the reaction of the 2-ene-l,4 dione with the thiol or thio acid of the formula R SH, an organic base is used. Hence, in addition to the foregoing compounds, the following compounds can be utilized in the, reaction with R SH:

Compound name R4 2-buten-L4 dial 2-methyl2-buten-1,4 dial Z-pentenalA-one 2-hexenalA-one 3-methyl-2-hexenal-4-on 2-methyl-2-pentenal-4-one- 2-methyl-2-heptenal4-one.- do Propyl 2-methyl-2-oetenal-4-one .do B

be carried out under reflux conditions although temperawhere the natural flavor is deficient in some regard, or tures varying from up to 60 C. are suitable and will supplementing the existing flavor or aroma impression to give rise to commercially suitable yields. When the reacmodify the organoleptic character. The materials which tion is carried out with highly volatile reactants, e.g., are so altered are generally referred to herein as conmethyl mercaptan, higher pressures than atmospheric pressumable materials.

sure are preferred, e.g., three atmospheres pressure. EX- Such 3-thia alkane-1,4 dione derivatives are accordingamples of reaction products, Z-thia-substituted-l,4-diones ly useful in flavoring compositions. Flavoring composiwhich are formed from the reaction of the 2-enel,4 tions are herein taken to mean those which contribute a diones with the thio acids, and thiols having the formula part of the overall flavor impression by supplementing or R SH are as follows: fortifying a natural or artificial flavor in a material, as

2-enel,4 dione react: nt RaSH reactant 3-thia substituted 1,4-dione reaction product '3-hexen-2,5-dione Thioacetic acid 3thioacetyl-2,5-hcxane dione.

Thiopropionic acid 3-thiopropionyl-4-rnetliyl hexane-2,5-dione. hiobcuzoic acid 4-thiobcnzoyl4-mcthyl hcptane-3,6-di0nc. 4-thiobcuzoyl4-ethyl hcptane-3,6-dione. 4-1;hioacetyl-5-ethyl0ctanc-3,6-dionc.

a-thiobutyryl-5-propyl heptanc3,6-dione; 3-otolylthio)-4-rnethyl hoptane-2,5dione.

do Thiobutyryl acid. o-Tolyl mercaptam.

Z-buterrlA-dial Thioacctic acid 2-thioacctyl-butanc-l,4-dial. 2-methyl2-buten-1,4-dial Thiobutyryl acid 2-thiobutyryl-3methyl butane-1,4-dial; 2-pentenal-4-oue 4-lnethyl-thi0 benzoic acid 2-thi0henzoyl-pentanall-one.

In addition to being reaction sequence intermediates, well as those which supply substantially all the flavor the Z-thia-substituted-1,4-diones as exemplified above are and/0r aroma character to a, consumable article. also useful for altering the organoleptic properties of con- The term foodstuff a used herein includes both solid sumable materials, more particularly, foodstuffs. Thus, for and liquid ingestible materials for man or animals, which p 3-thi0aCetY1-2,5-heXanedi0I1e h a roasted meal; materials usually do, but need not, have nutritional value. aroma and a pot-roast and r ast d meat flav r st d at Thus, foodstuffs includes meats, gravies, soups, conlevels of 5 p.p.m. Its flavor threshold Value is at 1 p-pvenience foods, malt and other alcoholic or non-alcoholic -M p ,5-hexanedione has a roasted meat aroma beverages, milk and dairy products, nut butters such as and a roasted meat flav r at Conc ntrat ns f 2 pp peanut butter and other spreads, seafoods including fish, with a hr h Value at P-P- The Compound crustaceans, mollusks and the like, candies, breakfast thiobenZ0Y1-2,5-hXanedi0n8 has a berry and a meat foods, baked goods, vegetables, cereals, soft drinks, snack aroma and an allium, earthy and horseradish flavor at conf d dog d t f d th veterinary d t d centrations of approximately 0.5 p.p.m. Its threshold h 1ik value is at 0.5 ppm. 3-Thiobenzoyl-2,5- at 5 When the 3-thia alkane-1,4-dione derivatives according p.p.m. evaluated in beef bouillon has a meaty note. 3-Merto hi invention are used i a f d flav i cOmPosi- CHPIO-ZJ-hEXaBediOIIB evaluated at P-P- adds 3 tion, they can be combined with conventional flavoring Slight p y note (which indeed is dasirable) t0 beef materials or adjuvants. Such co-ingredients or flavoring I bOHiUOfl- 3-Thioacetyl-2,5-hexanadione at 5 P-P- adds a adjuvants are well known in the art for such use and have burnt meat note t f bouillon. 3/ been extensively described in the literature. Apart from heXaflediOm adds Slightly green Chicken msat note to the requirement that any such adjuvant material be in- Chicken broth at P-P- 3-Thioacelyl-l5-hexanedione gestibly acceptable, and thus non-toxic or otherwise nonadds y chicken notes to chicken broth at P-P- 5 deleterious, conventional materials can be used and 3-MeYCaPt0-2:5"heXanedin adds chicken p y broadly include other flavor materials, vehicles, stato chicken broth at P-P- bilizers, thickeners, surface active agents, conditioners,

When used as intermediates, the thio-substituted-l,4- and im i diones of our invention are then cyclized to form sub- Examples f r f d fl i adjuvants :trtuted or unsubstituted 3-th1afurans according to the fol Methyl thiazole alcohol (4 methyl s fi hydroxyethyl owing reactlon.

thiazole); Z-Methyl butanethiol;

4-Mercapto-2-butanone; Q 3-Mercapto-4-pentanone; 0 0 O l-Mercapto-Z-propanone;

Benzaldehyde; wherein R and R are the same or different and are each F f l; hydrogen or lower alkyl; wherein R is either acyl or aroyl F f l l ohol; and R is hydrogen or lower alkyl. The resulting 3-thia Z-Mercapto propionic acid;

furans (novel compounds) may be used as such for their Z-Pentene; organoleptic properties or they may be hydrolyzed and Alkylpyrazinc;

then reacylated or aroylated to form other acyl thia or Methyl pyrazine;

aroyl thia substituted furans (other novel compounds) 2-Ethyl-3-methyl pyrazine; which have still other organoleptic properties useful for T nethyl pyrazine; flavoring foodstuffs. Polysulfides;

Thus, the 3-thia alkane-1,4-dione derivatives and mix- Di o yl disulfide; tures thereof according to the present invention can be Methyl benzyl disulfide; used to alter, vary, fortify, modify, enhance, or otherwise Alkyl thiophenes; improve the organoleptic properties, including flavor and/ 2-Butyl thiophene; or aroma, of a wide variety of materials which are in- 2,3-Dimethylthiophene; gested, consumed, or otherwise organoleptically sensed. S-Methylfurfural;

The term alter in its various forms will be understood Acetyl furan; herein to mean the supplying or imparting a flavor char- 2,4-Decadienal; acter or note to an otherwise bland, relatively tasteless Guiacol;

substance, or augmenting an existing flavor characteristic Phenyl acetaldehyde;

fi-Decalactone;

d Limonene;

Acetoin;

Amyl acetate;

Maltol;

Ethyl butyrate;

Levulinic acid;

Piperonal;

Ethyl acetate;

n-Octanal;

n-Pentanal;

Hexanal;

Diacetyl;

Monosodium glutamate; Sulfur-containing amino acids; Cysteine;

Hydrolyzed vegetable protein; Hydrolyzed fish protein; and Tetramethyl pyrazine.

The 3-thia alkane-1,4-dione derivatives, or the compositions incorporating them, as mentioned above, can be combined with one or more vehicles or carriers for adding them to the particular product. Vehicles can be edible or otherwise suitable materials such as ethyl alcohol, propylene glycol, water, and the like. Carriers include materials such as gum arabic, carrageenan, other gums, and the like. The 3-thia alkane-1,4-dione compounds according to this invention can be incorporated with the carriers by conventional means such as spraydrying, drum-drying, and the like. Such carriers can also include materials for coacervating the 3-thia a kane-1,4- dione derivatives (and other flavoring ingredients, as present) to provide encapsulated products. When the carrier is an emulsion, the flavoring composition can also contain emulsifiers such as monoand diglycerides of fatty acids and the like. With these carriers or vehicles, the desired physical form of the composition can be prepared.

The quantity of 3-thia alkane-1,4-dione derivatives or mixtures thereof utilized should be suflicient to impart the desired flavor characteristic to the product, but on the other hand, the use of an excessive amount of the derivative is not only wasteful and uneconomical, but in some instances too large a quantity may unbalance the flavor or other organoleptic properties of the product consumed. The quantity used will vary depending upon the ultimate foodstuff; the amount and type of flavor initially present in the foodstuff; the further process or treatment steps to which the foodstuff will be subjected; regional and other preference factors; the type of storage, if any, to which the product will be subjected; and the preconsumption treatment, such as baking, frying, and so on, given to the product by the ultimate consumer. Accordingly, the terminology effective amount and sufficient amount is understood in the context of the present invention to be quantitatively adequate to alter the flavor of the foodstutf.

It is accordingly preferred that the ultimate compositions contain from about 0.02 parts per million (p.p.m.) to about 250 p.p.m. of 3-thia alkane-1,4-dione deriv ative or derivatives. More particularly, in food compositions it is desirable to use from about 0.05 ppm. to 100 p.p.m. for enhancing flavors and in certain preferred embodiments of the invention, from about 0.2 to 50 ppm. of the derivatives are included to add positive flavors to the finished product. All parts, proportions, percentages, and ratios herein are by weight unless otherwise indicated.

The amount of 3-thia alkane-l,4-dione material or materials of our invention to be utilized in flavoring compositions can be varied over a wide range depending upon the particular quality to be added to the foodstuff. Thus, amounts of one or more derivatives according to the present invention of from about 2 ppm. up to 80 or 90 percent of the total flavoring composition can be incorporated in such compositions. It is generally found to be desirable to include from about 10 ppm. up to about 0.1 percent of the 3-thia alkane-l,4-dione derivatives in such compositions.

The following examples are given to illustrate embodiments of the invention as it is preferably preferred to practice it. It will be understood that these examples are illustrative and the invention is not to be considered as restricted thereto except as indicated in the appended claims.

EXAMPLE I (Preparation of cis-3-hexene-2,5-dione) In a 1000 ml. round bottom flask fitted with condenser and magnetic stirrer are placed 200 g. of 2,5-dimethoxy- 2,5-dimethyl-2,S-dihydrofuran and 200 ml. of a 1% aqueous acetic acid solution. The resulting solution is heated to reflux, refluxed for 2 minutes, cooled with an ice bath to 25 C. and 625 ml. of a 2% sodium bicarbonate solution is added. The solution is saturated by addition of 23 g. of sodium chloride and extracted with methylene chloride (1 200 ml. and 3X 100 ml.). After drying over sodium sulfate removal of the methylene chloride in vacuo gives 142 g. of crude cis-3-hexene-2,5-dione which by GLC analysis is about product having the structure:

EXAMPLE II (Preparation of 3-thioacetyl-2,5-hexanedione) In a 1000 ml. round bottom flask fitted with magnetic stirrer, thermometer, addition funnel and reflux condenser are placed 142 g. of crude cis-3-hexene-2,5-dione (ex Example I), 380 ml. of ether and 5 drops of piperidine. Thio acetic acid (96.6 g.) is added over a period of one hour. When about A; of the thio acetic acid is added the solution begins to reflux which continues during the remainder of the addition. After addition is complete the mixture is allowed to stand for 85 minutes. Ether is then removed in vacuo (water aspirator) to give 235 g. of crude material containing about 91% 3 thioacetyl-2,5- hexanedione. Distillation of a 134 g. portion of the crude gives 84.5 g. of 3-thioacetyl-2,S-hexanedione boiling at 86 to 87 C. at 0.5 torr. NMR, IR and mass spectral analysis confirm the structure:

EXAMPLE n1 (Preparation of 3-propylthio-2,5-hexanedione) In a 500 ml. flask fitted with thermometer, addition funnel, reflux condenser and magnetic stirrer are placed ml. of ether and one drop of piperidine. Addition of n-propanethiol is started and as the addition progresses more piperidine is added (33 drops total). After standing 18 hours, the solution is washed successively with 10% hydrochloric acid (2 7.5 ml), saturated sodium chloride solution (10 ml.), 5% sodium bicarbonate solution and saturated sodium chloride solution (2X 10 ml.). The ether solution is dried over sodium sulfate and concentrated to give 51.4 g. of a dark yellow oil. Analysis by GLC shows the material to be essentially pure-S-thiopropyl-2,5-hexanedione. Mass spectral analysis shows molecular ion 188 then descending order 43; 103, 41, 145, 71, 114 and 61 mile units.

EXAMPLE IV (Preparation of 3-mercapto-2,S-hexanedione) To ml. of a 2% sodium hydroxide solution in a flask fitted for stirring is added 10 g. of 3-thioacetyl-2,5-

hexanedione. After stirring for one hour the pH of the mixture is adjusted to 5-6 by the addition of dilute (10%) hydrochloric acid, the solution is saturated with sodium chloride solution and extracted with ether (4X 25 ml.). The ether extracts are combined, washed with saturated sodium chloride solution (15 ml.), dried and concentrated in vacuo to give 6.2 g. of crude 3-mercapto-2,5-hexane dione. Vacuum distillation gives 2.5 g. of 3-mercapto-2,5- hexanedione boiling at 5759 C. at 0.85 torr. NMR, IR and mass spectral analysis confirm the structure as 3-mercapto-2,5-hexanedione.

EXAMPLE V (Preparation of 2-thioacetyl-1,4-butane-dial) (A) Preparation of 2-butene-l,4-dial.A mixture of 2,5-dimethoxy-2,S-dihydrofuran (20 g.), water (80 ml.) and acetic acid (3 drops) is stirred for 105 minutes at room temperature, 22 minutes at 40 C. and 90 minutes between 60 C. and 75 C. GLC analysis at this point indicates 15.7% starting material and 83.5% 2-butene- 1,4-dial. The mixture is cooled to 25 C. and sodium bicarbonate (0.3 g.) is added.

(B) Preparation of 3-thioacetyl-l,4-butanedial.-To the aqueous solution obtained in A, supra, is added 10 g. of thiolacetic acid during a 14 minute period. During the addition, the temperature is kept below 30 C. by intermittent application of a cooling bath. After 110 minutes, the reaction mixture is extracted with methylene chloride (3X 35 ml.). The combined methylene chloride extracts are dried and then concentrated in vacuo to give 17.3 g. of yellow oil containing about 80% 2-thioacetyl- 1,4-butanedial. The compound is identified through mass spectral. NMR and IR analysis as having the structure:

M.S.-No molecular ion; remaining peaks in decreasing intensity-43, 29, 27, 45, 55, 60, 84, 100 and 142 m/e units.

NMR (CDCl 2.38 (s, 3) 3.02 (multiplet 2 1:10 Hz.), 4.46 (t, 1, 1:10 Hz.), 9.40 (s, l) and 9.68 (s, 1)

p.p.m.

IR (thin film)-2850, 2750, 1720, 1700 (shoulder), 1388, 1352, 1132 and 958 cm.-

EXAMPLE VI Preparation of 3-thioacetyl-4-oxo-pentanal) (A) 4-oxo-2-pental.Into a 5 liter, three-necked flask fitted with mechanical stirrer, thermometer and vacuum take-01f are placed 600 g. of 2-methyl-2,5-dimethoxy-2,5- dihydrofuran and 2400 ml. of deionized water. After 20 minutes of stirring at room temperature, the mixture become homogeneous and has a pale yellow green color. Analysis of a sample of the reaction mixture by GLC after 3.25 hours shows 22% methanol, 67% 4-oxo-2- pentanal and 9% starting material. Vacuum (26 torr) is applied to the reaction mixture while maintaining the temperature of the reaction mixture bewteen 25 and 30 C. After 3.25 hours GLC analysis shows 13% methanol, 82% 4-oxo-2-pentanal and 3.2% starting material. The vacuum is removed and the reaction mixture is allowed to stand at room temperature overnight. Analysis after standing overnight shows 12.9% mehanol, 85% 4-oxo-2- pentanal and 2.1% starting material.

(B) 3-thioacetyl-4-oxo-pentanal.--In a 5 liter, threenecked flask fitted with mechanical stirrer, thermometer and addition funnel are placed 2325 ml. of the solution obtained in (A) and 2 ml. of piperidine diluted in 5 ml. of water. To this solution is added a mixture of thiolacetic acid (292.3 g.) and piperidine (13 ml.) over a 20 minute period. After standing an additional 10 minutes, 20 ml. of concentrated hydrochloric acid is added, the resulting mixture poured into a separatory funnel and the oil layer removed. The aqueous layer is extracted with benzene (500 ml.) and methylene chloride (2X 500 ml.). The benzene extract is combined with the oil layer and the mixture is dried over sodium sulfate. The methylene chloride extracts are combined and dried over sodiumsulfate. Solvent removal in vacuo (40-45 bath at 15 torr) gives 414.5 g. of crude oil from the benzene extract and 172.5 g. of crude oil from the methylene chloride extracts.

EXAMPLE VII The following formulation is prepared:

Ingredient: Parts by weight Liquid hydrolyzed vegetable protein 90.00

4-Methyl-S-beta-hydroxy-ethyl thiazole 5.00 Tetrahydro thiophene-3-one 1.00 Furfuryl mercaptan 0.01 2-Nonenyl 0.50 Difurfuryl disulfide 0.49 Dimethyl sulfide 0.50 Methyl mercaptan 0.50 3-Thioacetyl-2,S-hexanedione 2.00

The 3-thioacetyl-2,5-hexanedione impart a roasted meat taste to the above formula and ties in and rounds up the other meat-like chemicals in the formula. When 3- thioacetyl-2,S-hexanedione is replaced by any one of the following compounds, a similar effect is imparted to the over-all flavor and aroma pattern of the above formula:

3-Mercapto-2,5-hexanedione 3-Thiobenzoyl-2,5-hexanedione.

What is claimed is:

1. A compound having the structure:

wherein R and R are the same or different and are either hydrogen or lower alkyl, R is lower alkanoyl, benzoyl, or methyl substituted benzoyl; each or R and R are the same or different and are either hydrogen or lower alkyl.

2. 3-Thioacetyl-2,S-hexanedione having the structure:

3. 3-Thiobenzoyl-2,5-hexanedione having the structure:

s 3 )l o References Cited Hermann et al.: Chemische Berichte, 104, 1971, pp. 492-513.

LEWIS GOTTS, Primary Examiner D. R. PHILLIPS, Assistant Examiner US. Cl. X.R. 

